Steel retainer



Patented Dec. 8, 1925.

UNITED STATES PATENT OFFICE. Y

WLLLIAM PRELLWITZ, OF EASTON, PENNSYLVANIA, lASSIIGNOR T ING-ERSOLL-RAND l COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPOBATIONVOF JERSEY.

STEEL RETAINER.

Application filed September 11, 1923. Serial No. 662,035.

To all 'whom t 'may concern: v Be it known that I, WILLIAM PKELL- wrrz, a citizen of the United States, and a resident of Easton, county of Northamp- 5 ton, and State of Pennsylvania, have invented a certain Steel Retainer, of which theJ following is a specilicationa accompanied by drawings.

The invention rela-tes to rock drills, but more particularly to drill steel retainers.

One object of the invention is to produce a drill steel retainer'which is strong vand rugged, but also adequately cushioned 'by suitable springs which take up the shock of the impact of the collar of the drill steel aga-inst the retainer and also serve to main l and guiding members.

Another object of the invention is to enable the retainer to he pivotally hungand tain the. retainer centered on, its supporting adjusted on their-ont head in a simple and convenient manner which` reduces' the num- Vber parts required andl prevents the reta1ner from springing outwardly, due to the jar imparted by the drill steel.

A further object is to secure means afvtording a. stop or bearing for the Vretainer against the front head, so that the retainer does not bear directly against the shank of the drill steel, thus leaving the drill steel free to rotate asrequired.

Further objects will hereinafter appear..V

Figure 2 is a view similar to Figure 1-v showing the position the parts assume when the drill steel 1s pulled out of a hole.

Figure 3 1s a transverse section taken on the line 3-3 of Figure l looking in the din In accordance with the'I present invention,l the front head A is formed with an upper recess J and an opposed lower recessgK. iange H of the front cylinder washer C 'forms a closure of one end of the recess J.

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A plunger L having a grooved head O is slidably disposed inthe rec-ess J and a coil spring P urges the kplunger LV outwardlyl from the recess J.

fAb'earing head S movable in the recess K has a stein Q slidable in the hole R in the front head vA and the head S is torniedwith a groove T and a notch U. Acoil spring X, one end of whiclrbears against the head S vis under constant compression lfor holding the head S in its outward position, and for cushioning the retainer. An auxiliary heavier springWwhich is not under compression normally bears against the shoulder V under thc'head S. The outer spring X is morey flexible than the inner spring W and compresses more rapidly in the downward movement of the head S. The outer spring X effects the locking of the retainer in proper operative position and takes the jar of the vdownward pull of the retainer. The center spring W may be added to further take they shock after the outer spring X has been compressed toa certain degree, so that the head S may be brought to a stop against the ten sion of the inner spring.

The steel retainer Y comprises side arms Z which are connected at their lower ends by the yoke a and at their outer ends by thev Wedge shaped cross piece b. The side arms Z are bowed at c in order to embracev and bear against thetront head A :and permit the yoke ci to encircle the steel@ but without touching` the steel. The retainer stops against the front head A as s wn in Figure 3 sothat the drill steel "'is free to rotate. The yoke a is formed with aY shoulder i al, which is adapted to receive'l-thecollar e of the drill ste`el G. ,The wedge shaped piece Z; is interposed betweent-he plunger L ics and the bearing head S, and has bearing both in the grooved head O of the plunger L and in theigroovei'I o--the headv S. Thev springs `P and X, and W cooperate to force' the wedge shaped connecting piece Z9- toward the bottom of thegroove T, so as to hold the yoke around ,the drill steelG as shown in Figure 2. IVhenever-it `is desiredto insert the drill steel G in the chuck F or remove it therefrom, the arms Z mayA be moved outwardly so thatv the wedge sh'aped piece o will catch in thenotch of the head S which will hold the arms ofthe f retainer in` their outward position, as shownin ldot and dash lines" in Figure l.'

Movement ofthe collar c ot the drill steel G-willnot b'epermitted beyond the shouh der (Zooftlre retainer, because, in the event orar'ry'y forcebeinfgeX-erted on the collar e, the yoke a will press more tightly againsterted on:v the" wedge shaped piece" Zi the grooveV T, and because the bearing'- edge of the wedge shaped piece o lies outwardly beyondtlre longitudinal axis of the bearing membersor heads O and S'. Vfheneverthe springs and*v WA are compressed, due to thev tendency ofthe drill steel G to move outwardly from the chuck F, the'plunger Ly will' followy up the-'wedge shaped piece o, due tof the expansion or-the coil spring l?, andthusse'rve to guidethe wedge shaped piece in itsy return movement. The wall of the" recess K is provided with a: groove K to permit the downward' movement of the wedge shaped piece b.

In orderI toI gua-rdf against'v excessive shocks and strains tothe springs W and X, the bottoni' of the groove K is'arranged with definite relation to the normalV position ofthe wedge' Z) and serves as a stop for h'ea'd'for retaining the steel within the front head, said v'yoke beiiigprovided with av'sin'gle cross piece, connecting the sides of the yoke, a grooved bearing head arranged slidably within the forward recessto support the yoke a plurality of springs to supportthecaring head, and a spring pressed plunger having a concave face cooperating with the cross piece to hold the -yoke in retaining and releasing position.

2'.' Inra steel retainer for rock drills, the combination of a front head having a single forward recess and asingle rearward recess, a drill steel supported by the front head, an endless yoke for retainingv the steel within the i front f head: comprising bowed arms to embrace-the front head-"and a crossl piece to connect the arms, said yoke being pivoted to one Side'of thelongitudinal axis of the machine, a bearinghead havingaI groove to st ipport the' yoke in retaining position and a notch to support the ,yoke in re* leasing position, said bearing 'headbeing arranged withinthe forwardrecess, aV` plurality of springs to support the bearinglread and absorb ithe "blow ofthe steel against) the yoke, and a spring" pressed plunger having aV concaveface'` to cooperatev with-the -CrOsspiece forholdingthe yoke in retaining" and releasingfposition. y

S-In a'steel retainer for rock drills, the combination of a frontylread''having av single forwardrecess and a single rearward recess, adrillsteel supportedo'by the front head, anl endless' yoke retainingl the steel within the:V front head comprising a pair of'arms tov embrace the front head andv a cross 4piece formed integral with thev arms to provide a. single bearing for said yoke, said yoke being pivoted to one side of the longitudinal 4axis of the machine, a bearing head in said o'rward recess to support the yoke, said bea-ring head having a' groove and a notch in one face to vsupport the yoke in retaining and releasing positions` a plurality of springs in the forward recess to absorb the blow ofthe drill steel yagainst the yoke, a spring pressed plunger in the rearwardrecess, said plunger having a concave face to cooperate with the crosspiece` for holding the yoke in retaining and releasing positions, anda stop for limiting the movement oil' the yoke in one dlre'ction.4 p A Y o n In testimony whereolv I have signed this specification."

- WILLIAMPRELLWITZ'. 

